The present disclosure generally relates to micro-vaporizers and particularly to micro-vaporizers for small handheld devices.
Vaporizers convert a liquid or solid into a vapor typically by heating to promote evaporation. Many products have micro-vaporizers that typically vaporize liquids at a rate of less than 50 milliliters per hour (ml/h). The vapor may be inhaled, dispersed in the air to create a scent, or used in some other manner. Micro-vaporizers may be used in products such as electronic cigarettes, fragrance dispensers, milliliters per hour mosquito, or other bug repellent diffusers, air and environment purification units, and essence or aromatic diffusers.
Micro-vaporizers may be used in electronic cigarettes to produce a vapor from nicotine liquid in place of the smoke created by the burning of tobacco products. As a user inhales from an electronic cigarette, a flavored, nicotine-containing liquid contained in the cigarette is heated to produce vapor. A battery in the cigarette may be used to power a heating element. The heater rapidly heats the liquid to generate the vapor that simulates smoke.
Users may prefer that their electronic cigarettes have characteristics similar to tobacco cigarettes. The size and shape of both types of cigarettes may preferably be about the same. Tobacco cigarettes generate smoke almost instantaneously when a user inhales. An electronic cigarette preferably also generates vapor almost instantaneously. Tobacco cigarettes are generally cheap and disposable; thus, cheap and disposable electronic cigarettes may also be commercially desirable.
Structurally, conventional electronic cigarettes use fiber strings to draw or direct liquid stored in a reservoir towards the surface of a heating element to vaporize the liquid. The fiber strings are directly in contact with the surface of the heating element. The conventional fiber strings may have problems in the heat transfer efficiency and fluid leakage.
In the conventional structure, liquid is directed or drawn by a fiber string that is in close or direct contact with the heating element surface. Because liquid is absorbed by the fiber strings, vaporization occurs on the surface of the fiber string. Consequently, mainly the liquid on the surface of the fiber strings is vaporized and remainder of the liquid absorbed into the fiber strings is heated but does not vaporize. Heating a liquid that do not vaporize causes excessive power usage, which may drain the battery in the cigarette.
The conventional fiber string structure tends to allow liquid to leak because the liquid continues to seep into fiber string while the cigarette is not in use. The liquid absorbed in the fiber string may leak through the open vapor channel and exit through the mouthpiece.
Further, fiber strings tend to absorb liquid in proportion to the diameter of the string. The amount of liquid adsorbed by the strings generally is more than the amount of liquid needed to convert to vapor in a volume that a user may desire during a single inhalation.
Also if a user applies a small suction force, the excessive amount of vapor in the vapor channel may condense and become a liquid form. The condensed liquid may be unable to be recaptured and vaporized, and thus leak through the mouthpiece.
Electronic cigarettes typically have a heating element that quickly heats up to generate vapor. Other types of conventional vaporizers may use a direct flame to vaporize liquid but flames may not be suitable for an electronic cigarette.
Further, a user may need to learn and become accustomed to an electronic cigarette or other type of vaporizer. The user may need to adjust to the heating time and method of each type of conventional vaporizers. For example, the conventional vaporizers that use tube delivery systems may require the users to learn the proper draw speed of the vaporizer, and the vaporizers that use flame powered units may need to learn the correct flame distance and draw.
One type of commercially desirable electronic cigarette shape may be similar to a conventional tobacco cigarette. It may be challenging to develop electronic cigarettes that have characteristics similar to tobacco cigarettes, such as the small diameter, cylindrical shape, and compact portability of a tobacco cigarette. One of the difficulties is that the desired shape and size of a conventional tobacco may not fit conventional batteries, such as an alkaline battery. The electrical energy discharge rate needed to heat and vaporize the liquid in an electronic cigarette may exceed the energy stored in low-cost conventional batteries and conventional rechargeable batteries. Batteries that store and discharge large amounts of energy, such as lithium batteries, are typically expensive, and may not be viable for a disposable electronic cigarette.
In view of these challenges and others, there continues to be a long felt and unmet need for low cost, lower energy consumption, and controllable vapor capacity micro-vaporizers for electronic cigarettes and other similar devices.